Washington state's whooping cough epidemic continues to spread at a rapid pace, infecting more than 80 children in a matter of days and showing a heavy presence in Clark County.

State data show 387 reported cases so far this year, up from just 85 by this time in 2014. Of that total, more than 14 percent occurred in Clark County.

The bacterial infection's spread spurred Clark County public health officials to issue a health advisory earlier this month. The agency also sent letters home to parents whose children attend school with infected students.

County public health spokesman Don Strick said 80 percent of the Clark County patients are younger than 18.

"We're treating this as a community-wide issue," Strick said. "Everyone needs to be thinking about taking protective measures and getting vaccinated."

The epidemic has not spread into Oregon.

Washington health officials, who released the data Tuesday, said babies too young for vaccination and teens with waning protection were particularly at risk.

Clark County had the second-highest number of cases in the state at 54, based on data collected Saturday and released Tuesday. It trailed only Kitsap County's 85 cases. King County, home to Seattle, rounded out the top three at 53 cases.

By Tuesday, Clark County officials put the local tally at 73 -- a 35 percent jump in four days.

Pertussis rates range widely among counties, with Walla Walla, Jefferson and Kitsap counties reporting at least 34 per 100,000 people, and King County reporting only 2.7 cases per 100,000 people.

Fifteen counties have reported zero cases of pertussis.

Pertussis causes uncontrollable coughing that can make it hard to breathe and cause a characteristic "whooping" sound in someone struggling to get air. An outbreak in 2012 ended with nearly 5,000 reported cases and one death.